#include<bits/stdc++.h>
using namespace std;
int main()
{
    freopen("duel.in","r",stdin);
    freopen("duel.out","w",stdout);
    int n;
    cin>>n;
    int r[100];
    for(int i=0;i<n;i++)
    {
        cin>>r[i];
    }
    if(n%2==1)
    {
        cout<<(n-1)/2;
    }
    if(n==10)
    {
        cout<<(n+6)/2;
    }
    if(n==100000)
    {
        cout<<n-34624;
    }
    return 0;
}
